Title :
Control of FSG/SiO2 interlayer conditions to prevent Al-wiring delamination caused by F accumulation at Ti/SiO2
Author :
Kawashima, Yoshiya ; Ichikawa, Toshihiko ; Nakamura, Norio ; Kawano, Hideo ; Ide, Takashi ; Obata, Syu ; Den, Yasuhide ; Kudo, Masahiro
Author_Institution :
ULSI Device Dev. Div., NEC Corp., Kanagawa, Japan
Abstract :
The optimum conditions of a fluorinated silica glass/SiO2 (FSG/SiO2) interlayer were investigated for preventing Al-wiring delamination. TiFx formation by F atoms transported from the FSG film to the Ti/SiO2 interface during the metallization process induced the delamination. Correlation between the Al-wiring delamination and F concentration at Ti/SiO2 was demonstrated by a 3-D mapping of F concentrations at Ti/SiO2 with various thickness of SiO2 film and F content in the FSG film. Some treatments of the FSG/SiO2 interlayer to reduce F accumulation at Ti/SiO2 were also examined. It was revealed that more than 4500-Å thickness and strain relaxation of the compressive SiO2 film were effective for F reduction at Ti/SiO2. On the other hand, F concentration at Ti/SiO2 was independent of F content in the FSG film in the range of 2-5 %. F content in FSG film should be kept as much as possible, that is, 4-5 % not to increase the capacitance between adjacent metal lines. The Al-wiring delamination was prevented by introducing these parameters of the FSG/SiO2 interlayer into the fabrication line
Keywords :
aluminium; delamination; fluorine; integrated circuit manufacture; integrated circuit metallisation; metal-insulator boundaries; silicon compounds; titanium; 4500 A; Al; Al wiring delamination prevention; F; F accumulation; FSG/SiO2 interlayer conditions control; SiO2 film thickness; Ti-SiO2; Ti/SiO2 interface; TiF; TiFx formation; capacitance; compressive SiO2 film; fluorinated silica glass/SiO2 interlayer; metallization process; strain relaxation; Atomic layer deposition; Atomic measurements; Delamination; Electrons; Metallization; Plasma measurements; Semiconductor device measurement; Semiconductor films; Silicon; Tin;
Conference_Titel :
Semiconductor Manufacturing Symposium, 2001 IEEE International
Conference_Location :
San Jose, CA
Print_ISBN :
0-7803-6731-6
DOI :
10.1109/ISSM.2001.962938
